Do Migrating Birds Follow Power Lines or Pylons? (1 Viewer)

I hadn't really thought about this before but a friend recently suggested to me that some migrating birds follow the power lines/pylons. I live in inland rural Sussex and 100 metres from my house is a HUGE pylon, part of the National Grid marching up from Dungeness Power Station. It goes NW/W across inland Sussex. I've seen good birds here. The current count is 88, increased by one today (raven). Habitat is mixed farmland, grass and arable with small fields broken up by woodland copses. The goodies include hen harrier, honey buzzard, osprey, red kite and possibly a Montague's harrier. We get big flocks of fieldfare and redwing passing through. And in the last week I counted 600+ hirundines in less than an hour one day.

So my question is: is there evidence, anecdotal or proven, that shows that some migrating birds follow power lines/pylons? Is it to do with the magnetic field generated by them? Or is it a visual thing, like markers: for example, like a river valley funnels hirundines through?

Joanne

joannechattaway said:

part of the National Grid marching up from Dungeness Power Station.

The current count is 88

Joanne

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Is that gigawatts Joanne?

I see birds following many visual lines - rivers, roads, valleys...I know my local church steeple acts as a beacon/guide to passing birds. The fact that I live near a canal & river, along a natural ridge too, means there's a concentration of bird routes near here.
I've always suspected the power lines are a route-finder too.
I wonder though, if they weren't aligned in the correct direction, whether birds would follow them.
Certainly returning migrants which know their landscape and route use visual signals to find their way, at least to some degree - as do some insects on a smaller scale.

H

I have heard of migrating birds following the UK's motorway network, so I suppose they would follow power lines, too.

Its always amazed me why Upton Warren (Worcs) attracts all the good birds that it does. Could it be the fact that the M5 motorway (junction 5) lies less than a mile away and two very high radio/tv transmitters overlook the reserve.

halftwo said:

I wonder though, if they weren't aligned in the correct direction, whether birds would follow them.


H

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... in Sussex the powerlines running from Dunge take an East to west direction overall and not I suspect that which would be the normal migratory direction for raptors hitting the South Coast. In general, in Sussex, the vis migs are more likely to have come in off the sea in Sussex rather than Kent imo, since main influx (ie not local breeders) are still traveling in a northerly direction overall. Diurnal migrants, such as Osprey are more likely to use rivers/lakes/coasts as visual markers I would have thought requiring as they do, hunting grounds for feeding during migration . Also, depends on species and whether they are nocturnal or diurnal migrants - main 'maps' are Sun, Stellar and geomagnetic maps and migration flight 'time' clocks, rather than man-made constructions such as powerlines and communication installations (which I would have thought are more likely to create magnetic abnomalities in geomagnetic pulses and present collision risks with power lines rather than assist particularly!). For nocturnal migrants, artificial light pollution given off from communication towers and windfarms (motorway traffic? airports?) for example, may be actually be factor in disorientation (especially considering the lower spectral light sources vis a vis avian visual reception) since birds apparently can get 'trapped' in a light pool when there is nocturnal cloud cover blocking moonlight and stellar markers. I think studies have been done in the States (albeit different ecological factors regarding migration) to suggest birds use varying degrees of a combination of geo-magnetic/geo-visual/and solar/stellar mapping along with genetic imprinting but it's still a subject that fascinates and subject to further scientific research for definitive explanations of how individual species migrate.

In my experience, it's not unusual to see very large flocks of hirundines and (smaller!) flocks of passerines moving through various locations in the County during migration periods since many smaller bird species arrive together in flocks before dispersing to individual breeding locations or tend to gather in larger flocks again before moving across the channel south for their winter quarters. I imagine, birds do use man-made visual markers but rather as a fall back perhaps during migration/or have been disorientated towards them. They may use them at times to establish individual breeding territory boundaries at a local level, rather than them playing a particularly significant contribution in helping them 'finding their way' around the spatial distances covered during long distant migration. Some Hirundine sp. and Starlings do use powerlines for gathering on on during migration times in Sussex, so perhaps this could account for high density around powerlines in some instances.

Thanks people for your comments. We do seem to be on some kind of minor flyway and I just wondered if the pylons contributed to this in any way, be it as markers or whatever. But being less than 20 miles from the Sussex coast is the more obvious explanation. I just wondered if the power lines aided them in any way, had any bearing on the spread and movement of birds. The answer seem to be yes. For years I have hated the site of this pylon from my house but I'm now seeing it in a different light.

In the case of red kite and raven which are not migratory but are spreading into and across Sussex from the west, could they have followed the lines? Are they aiding their spread?

Joanne

joannechattaway said:

So my question is: is there evidence, anecdotal or proven, that shows that some migrating birds follow power lines/pylons?

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Studies have shown that while all the usual factors such as magnetic imprint, stars, etc, take birds on the bulk of their migration, many species do use local landmarks to retrace parts of their journey, particularly to the local area. For returning birds, I'd have thought it sensible to assume a distinctive land feature, such as power lines, could form that map, equally as well as a stream course or river, etc.

We have a fairly minor, but quite noticeable fly-way past the edge of the village, (Just north of Southampton). There is a fairly prolific network of power lines in the area mainly east to west, but the migratory birds don't seem to be influenced by these.
I've suspected the birds I see have taken a wrong turning along Southampton Water, and headed up the Itchen instead of the Test Valley (which is a more prolific flyway).
When the Itchen dwindles to a small stream, they cut across the edge of where i live, perhaps using a local TV Transmitter mast, Romsey Abbey, or Mottisfont as landmarks.
Whatever it is, I'm not complaining!

The local Corvids and Pigeons however do seem to follow these lines daily, but this could just be coincidence.. The only way to prove this would be to chop them all down one night!

Often wondered about Transmitter masts, especially those with a red warning light on top maybe acting as a magnet for migrants, e.g. Upton Warren mentioned above. My previous local patch "Quainton Hill" in bucks had a transmitter and a lot of migrants, however, was the only hill for a few miles. I've noticed a transmitter mast on one of the many hills north of me in the Wiltshire Downs, so I'm meaning to experiment there sometime.

gyrfalcon said:

Whatever it is, I'm not complaining!

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:t: That's my feeling too.